| Author | Message | ||
     Patrick_atlanta |
I would like to upgrade the top end, but also want to keep it on a budget. I am going to do the following, so any advice would be appreciated: 1. Swap out the cams. I would like to keep bottom end and midrange power, as I mostly mountain ride in Georgia. Suggestions on suppliers and/or specific grinds. Do the manufacturers supply data regarding advance with their cams? After reading posts I’ve come to realize that not all cams will drop into this motor. This is a definite pit fall I would like to avoid. 2. Blend the heads. I have read the infinite posts regarding this subject. Conclusions remain the same, send them to a shop. However, I want to open up the ports a “little” and smooth out the flow paths where applicable. Anyone out there has done this themselves with success. 3. Increase displacement. Pistons/rings are cheap. Recommended oversizes and suppliers would be appreciated. Existing “upgrades” on the bike include Kuryaken air filter assembly, Bubs pipes, and rejetting. I have not seen a single positive post regarding the Bubs pipes. I do have the stock header pipe as well. I can also fabricate a 2.50” pipe (the “old” pro series diameter). Would it be beneficial to go back to the collector configuration? I will also post this question in the exhaust section. Thanks, Patrick | ||
| Spooky |
Patrick, Contact Aaron Wilson at NRHS. He can point you in the right direction. Eric | ||
| Cerbero |
which küryakyn air filter do you have? how does it look/feel/sound? i also have a 97 M2 and i've been meaning to swap the carbon fiber ham can with something more distinctive. | ||
| Captainkirk |
Patrick, Go to the Andrews website for cam grind info (my brother also rides a '97 M2 and likes the N8 grind). I don't know if they're a sponsor or not- if not, it may not be cool to post a link- so if you can't find the site let me know. Heads are not cheap, let Aaron's fingers do the walking. Race header with race pipe seems the best combo, second best would be (IMHO)stock header with D&D slip on. D&D also has a COMPLETE exhaust system now. Of course, Force does (and has) but IMHO it's way too loud for street use. Unless you have a penchant for meeting neatly dressed individuals with little or no sense of humor. Also, if your bike does not have Thunderstorm heads, suggest swapping for them or better yet, XB heads. Check with Aaron.  | ||
| Blake |
Also consider giving Cycle-Rama a call. Bottom line, you are as likely to hurt performance as help it if you try to work the heads yourself. There is little to nothing that is intuitive in high performance headwork. A set of XB heads would be great as they can be used with your stock flat top pistons. Thunderstorm heads will require compatible domed pistons to maintain a 10:1 compression ratio and thus performance. If it were me, I'd go with the SE 537 cams or the new XB grind cams and the XB heads with a basic porting/blending job. You can sell your lightning heads on ebay for a good chunk of change... pistons too if you decide on new ones. Lot's of sportster guys aren't looking to rev past 6,250 rpm but are looking for Buell heads that will provide improved performance as a bolt-on. If compression and leak-down are within spec, I'd have the stock cylinders rehoned and install new rings including a total seal second compression ring. If compression and/or leakdown is indicating poor piston-ring to cylinder sealing, I'd either want to have the cylinders overbored and honed by an expert shop, or I'd purchase a set of new ones of the nicasil all-aluminum type. Ask the performance shop who does your heads what exhaust will best suit your needs. That can always be saved for upgrade later on. Let us know what you end up with. OH! Be sure to have your bike dyno tested by a competent technician BEFORE making any changes, and INSIST that said dyno testing include air/fuel ratio measurements (dyno must have an 02 sensor, commonly called a "sniffer"  . Expect low to mid 70 rwhp. |
